VAT on a service provided in the UK?

I am working for a training provider in the UK that is VAT registered. We are running a training course in June that will be held in the UK and I have one guy coming on the course who is coming over from Nigeria. When I rang HMRC they asked how the guy would be paying, i.e. as a student or if a company would be paying on his behalf. I thought that he would be paying for himself, and based on this the HMRC said that VAT should be charged as it is where the event takes place. ..but Iv'e been told now that there may be a chance that his company will pay for him. Would this affect the vat that I charge on the invoice? (his company is also in Nigeria)